tolong bantu. carikan cara nya

19.
r = 47-35 = 12 cm
s = √35²+12² = √1.225+144 = √1.369 = 37 cm

Lp = 2πr² + πrs
= πr(2r + s)
= π x 12 x (24 + 37)
= π x 12 x 61
= π x 732
= 732π cm²

20.
CD = 80/50 x 40 = 320/5 = 64 cm